Uninsured vs. Underinsured Motorist Coverage in Illinois
Illinois UM pays when the other driver is uninsured or a hit-and-run. UIM applies when the other driver's limits are less than your UIM limits, and pays your UIM limit less what you actually recovered.
Minimums and required UM
625 ILCS 5/7-203 sets the minimum liability limits at $25,000 for one person, $50,000 for two or more and $20,000 for property damage, and 215 ILCS 5/143a requires UM in those limits. UM must equal your bodily injury liability limits unless you reject the excess in writing.
When a driver is underinsured
A vehicle is underinsured when the sum of the limits of liability under all bodily injury policies or bonds applicable to the driver and the vehicle is less than the limits of underinsured coverage provided to you. It compares limits with limits, not with your damages. UIM must equal total UM where UM exceeds the minimum (143a-2(4)).
How UIM pays
The insurer's limit is the UIM limit less the amounts actually recovered under the applicable bodily injury policies, bonds or other security on the underinsured vehicle. With $100,000 of UIM and $25,000 recovered, the most is $75,000.
Settlement rules
If your insurer is notified in advance of a proposed settlement and does not advance a payment equal to it within 30 days, it cannot exercise subrogation against the underinsured driver (143a-2(6)). A policy may deny payment until the other driver's limits are exhausted, but a settlement for less than the limits does not bar a UIM claim (143a-2(7)).
Deadlines and next steps
An action for injury to the person must be commenced within 2 years (735 ILCS 5/13-202). Stacking is a separate question; see our statute post and the explainer, then use the Illinois UM/UIM stacking calculator.
A local personal injury attorney can review your claim — many offer a free consultation.
This is general information, not legal advice, and the state comparisons above are illustrative, not an exhaustive survey. Confirm how Illinois's rules apply to your specific case with a licensed Illinois attorney.